/* Layout: чертёжная сетка на стальном фоне; квиз — главный «лист» страницы, справа штамп с параметрами проекта. */
:root {
  --bg: #e9edf0;          /* оцинкованная сталь */
  --surface: #f8fafb;
  --ink: #15212b;         /* графит */
  --muted: #56636e;
  --line: #c6cfd6;
  --grid: rgba(21, 33, 43, 0.055);
  --accent: #f2a900;      /* сигнальный жёлтый RAL 1003 */
  --accent-ink: #1b1400;
  --accent-soft: rgba(242, 169, 0, 0.16);
  --steel: #2e4a5f;       /* грунт по металлу */
  --panel: #15212b;
  --on-panel: #e9edf0;
  --danger: #b3261e;
  --ok: #2f7d4f;

  --font-display: "Oswald", "Arial Narrow", "Roboto Condensed", sans-serif;
  --font-body: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --r: 6px;
  --shadow: 0 1px 0 rgba(21, 33, 43, 0.06), 0 12px 32px -18px rgba(21, 33, 43, 0.35);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f161c; --surface: #17212a; --ink: #e5ebef; --muted: #98a6b1; --line: #2b3a46;
    --grid: rgba(229, 235, 239, 0.045); --accent: #ffb81c; --accent-ink: #1b1400;
    --accent-soft: rgba(255, 184, 28, 0.14); --steel: #8fb3cc; --panel: #1f2d38; --on-panel: #e5ebef; --danger: #ff8a80; --ok: #7fd1a0;
    --shadow: 0 1px 0 rgba(0, 0, 0, 0.3), 0 16px 40px -20px rgba(0, 0, 0, 0.8);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f161c; --surface: #17212a; --ink: #e5ebef; --muted: #98a6b1; --line: #2b3a46;
  --grid: rgba(229, 235, 239, 0.045); --accent: #ffb81c; --accent-ink: #1b1400;
  --accent-soft: rgba(255, 184, 28, 0.14); --steel: #8fb3cc; --panel: #1f2d38; --on-panel: #e5ebef; --danger: #ff8a80; --ok: #7fd1a0;
  --shadow: 0 1px 0 rgba(0, 0, 0, 0.3), 0 16px 40px -20px rgba(0, 0, 0, 0.8);
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background-color: var(--bg);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 24px 24px;
  color: var(--ink);
  font: 400 16px/1.55 var(--font-body);
  -webkit-font-smoothing: antialiased;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
img, svg { max-width: 100%; }
a { color: inherit; }
h1, h2, h3 { font-family: var(--font-display); font-weight: 600; line-height: 1.08; text-wrap: balance; margin: 0; letter-spacing: 0.005em; }
p { margin: 0; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

.wrap { width: 100%; max-width: 1180px; margin-inline: auto; padding-inline: 20px; }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.eyebrow {
  font: 500 12px/1.2 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted);
}

/* Header */
.top { position: sticky; top: env(safe-area-inset-top, 0px); z-index: 20; background: var(--surface); border-bottom: 1px solid var(--line); }
.top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-block: 12px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; min-width: 0; }
.brand svg { flex: none; color: var(--ink); }
.brand b { font: 600 18px/1 var(--font-display); text-transform: uppercase; letter-spacing: 0.04em; }
.brand small { display: block; font: 400 12px/1.3 var(--font-body); color: var(--muted); }
.top-right { display: flex; align-items: center; gap: 16px; }
.top-phone { font: 500 15px/1 var(--font-mono); text-decoration: none; white-space: nowrap; }
@media (max-width: 640px) { .brand small, .top-phone { display: none; } }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 48px; padding: 12px 22px; border-radius: var(--r); border: 0; cursor: pointer;
  font: 600 16px/1 var(--font-body); text-decoration: none; transition: transform 0.12s, background-color 0.15s, opacity 0.15s;
}
.btn-accent { background: var(--accent); color: var(--accent-ink); box-shadow: inset 0 -3px 0 rgba(0, 0, 0, 0.18); }
.btn-accent:hover { transform: translateY(-1px); }
.btn-accent:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }
.btn-ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--ink); }
.btn-sm { min-height: 40px; padding: 10px 16px; font-size: 14px; }

/* Hero */
.hero { padding-block: 56px 40px; }
.hero .wrap { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr); gap: 48px; align-items: center; }
.hero h1 { font-size: clamp(34px, 5.2vw, 60px); text-transform: uppercase; margin-block: 14px 18px; }
.hero h1 em { font-style: normal; color: var(--ink); background: linear-gradient(transparent 62%, var(--accent) 62%, var(--accent) 92%, transparent 92%); padding-inline: 2px; }
.hero .lead { font-size: 18px; color: var(--muted); max-width: 34em; }
.hero-cta { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; margin-top: 28px; }
.hero-cta span { font-size: 14px; color: var(--muted); }
.facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; margin-top: 36px; border-top: 2px solid var(--ink); }
.facts div { padding: 14px 16px 0 0; }
.facts div + div { padding-left: 16px; border-left: 1px solid var(--line); }
.facts b { display: block; font: 600 26px/1.1 var(--font-display); }
.facts span { font-size: 14px; color: var(--muted); }
.drawing { color: var(--steel); }
.drawing .dim { font: 500 13px var(--font-mono); fill: var(--muted); }
.drawing .lbl { font: 500 11px var(--font-mono); fill: var(--muted); letter-spacing: 0.08em; }
@media (max-width: 900px) {
  .hero { padding-block: 32px 24px; }
  .hero .wrap { grid-template-columns: 1fr; gap: 24px; }
  .drawing { order: -1; max-width: 520px; }
}
@media (max-width: 480px) {
  .facts { grid-template-columns: 1fr; }
  .facts div + div { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); padding-bottom: 12px; }
  .facts div { padding-block: 12px; }
}

/* Quiz */
.quiz-sec { padding-block: 24px 64px; scroll-margin-top: 72px; }
.quiz-shell { display: grid; grid-template-columns: minmax(0, 1fr) 300px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); box-shadow: var(--shadow); overflow: hidden; }
.quiz-main { padding: 32px 36px 28px; min-width: 0; display: flex; flex-direction: column; min-height: 560px; }
.quiz-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.progress { height: 6px; background: var(--line); border-radius: 3px; margin-block: 14px 28px; overflow: hidden; }
.progress i { display: block; height: 100%; width: 0; background: var(--accent); transition: width 0.35s ease; }
.q-title { font-size: clamp(24px, 3vw, 34px); }
.q-hint { color: var(--muted); margin-top: 8px; max-width: 46em; }
.q-body { margin-top: 24px; flex: 1; }
.q-step { animation: stepIn 0.3s ease both; }
@keyframes stepIn { from { opacity: 0.4; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.opts { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 210px), 1fr)); gap: 12px; }
.opts.wide { grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr)); }
.opt {
  position: relative; display: flex; align-items: flex-start; gap: 12px; padding: 16px; min-height: 64px;
  border: 1.5px solid var(--line); border-radius: var(--r); background: var(--surface); color: var(--ink);
  font: 500 16px/1.3 var(--font-body); text-align: left; cursor: pointer; transition: border-color 0.15s, background-color 0.15s;
}
.opt:hover { border-color: var(--steel); }
.opt[aria-pressed="true"], .opt[aria-checked="true"] { border-color: var(--accent); background: var(--accent-soft); }
.opt .mark { flex: none; width: 20px; height: 20px; margin-top: 1px; border: 1.5px solid var(--muted); border-radius: 50%; display: grid; place-items: center; }
.opt.multi .mark { border-radius: 4px; }
.opt[aria-pressed="true"] .mark, .opt[aria-checked="true"] .mark { border-color: var(--accent); background: var(--accent); }
.opt[aria-pressed="true"] .mark::after, .opt[aria-checked="true"] .mark::after {
  content: ""; width: 9px; height: 5px; border: 2px solid var(--accent-ink); border-top: 0; border-right: 0; transform: translateY(-1px) rotate(-45deg);
}
.opt small { display: block; margin-top: 4px; font-weight: 400; font-size: 14px; color: var(--muted); }
.opt .ico { flex: none; width: 34px; height: 34px; color: var(--steel); }

.range-box { max-width: 640px; }
.range-val { display: flex; align-items: baseline; gap: 10px; }
.range-val b { font: 600 64px/1 var(--font-display); font-variant-numeric: tabular-nums; }
.range-val span { font: 500 22px var(--font-display); color: var(--muted); }
.range-dims { margin-top: 6px; color: var(--muted); font-size: 15px; }
input[type="range"] { width: 100%; margin-block: 24px 6px; accent-color: var(--accent); height: 28px; }
.range-scale { display: flex; justify-content: space-between; font: 500 12px var(--font-mono); color: var(--muted); }
.check-line { display: inline-flex; align-items: center; gap: 10px; margin-top: 22px; cursor: pointer; font-size: 15px; }
.check-line input { width: 18px; height: 18px; accent-color: var(--accent); }

.field { display: grid; gap: 6px; }
.field label { font-size: 14px; font-weight: 500; }
.field label i { font-style: normal; color: var(--danger); }
.field label small { color: var(--muted); font-weight: 400; }
.field input {
  width: 100%; min-height: 50px; padding: 12px 14px; border: 1.5px solid var(--line); border-radius: var(--r);
  background: var(--bg); color: var(--ink); font: 400 17px var(--font-body);
}
.field input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.field input[aria-invalid="true"] { border-color: var(--danger); }
.field .err { min-height: 18px; font-size: 13px; color: var(--danger); }
.region-extra { margin-top: 18px; max-width: 460px; }

.contact-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px 16px; max-width: 680px; }
.contact-grid .full { grid-column: 1 / -1; }
@media (max-width: 560px) { .contact-grid { grid-template-columns: 1fr; } }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { min-height: 40px; padding: 8px 14px; border: 1.5px solid var(--line); border-radius: 999px; background: transparent; color: var(--ink); font: 500 14px var(--font-body); cursor: pointer; }
.chip[aria-checked="true"] { border-color: var(--accent); background: var(--accent-soft); }
.consent { display: flex; gap: 10px; align-items: flex-start; font-size: 13px; color: var(--muted); margin-top: 6px; cursor: pointer; }
.consent input { flex: none; width: 18px; height: 18px; margin-top: 1px; accent-color: var(--accent); }
.hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.form-err { color: var(--danger); font-size: 14px; margin-top: 12px; }

.quiz-nav { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 28px; padding-top: 20px; border-top: 1px dashed var(--line); flex-wrap: wrap; }
.quiz-nav .note { font-size: 13px; color: var(--muted); }

/* Штамп — сводка параметров, как угловой штамп на чертеже */
.stamp { background: var(--panel); color: var(--on-panel); padding: 28px 24px; display: flex; flex-direction: column; gap: 18px; min-width: 0; }
.stamp h3 { font-size: 20px; text-transform: uppercase; letter-spacing: 0.04em; }
.stamp dl { margin: 0; display: grid; gap: 0; border-top: 1px solid color-mix(in srgb, var(--on-panel) 25%, transparent); }
.stamp dl > div { display: grid; grid-template-columns: 96px minmax(0, 1fr); gap: 10px; padding-block: 9px; border-bottom: 1px solid color-mix(in srgb, var(--on-panel) 18%, transparent); font-size: 14px; }
.stamp dt { color: color-mix(in srgb, var(--on-panel) 62%, transparent); font: 500 11px/1.6 var(--font-mono); text-transform: uppercase; letter-spacing: 0.08em; }
.stamp dd { margin: 0; overflow-wrap: anywhere; }
.stamp dd.empty { color: color-mix(in srgb, var(--on-panel) 40%, transparent); }
.stamp .gift { margin-top: auto; padding: 14px; border: 1px dashed var(--accent); border-radius: var(--r); font-size: 14px; }
.stamp .gift b { color: var(--accent); display: block; font: 600 15px var(--font-display); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 4px; }
@media (max-width: 900px) {
  .quiz-shell { grid-template-columns: 1fr; }
  .quiz-main { padding: 22px 18px 20px; min-height: 0; }
  .stamp { padding: 20px 18px; }
  .stamp dl > div { grid-template-columns: 110px minmax(0, 1fr); }
}

/* Done */
.done { text-align: left; max-width: 620px; }
.done .badge { width: 56px; height: 56px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); display: grid; place-items: center; margin-bottom: 18px; }
.done h2 { font-size: clamp(28px, 3.4vw, 40px); }
.done p { margin-top: 12px; color: var(--muted); }
.done .demo-note { margin-top: 18px; padding: 12px 14px; border-left: 3px solid var(--accent); background: var(--accent-soft); color: var(--ink); font-size: 14px; }

/* Sections */
.sec { padding-block: 64px; }
.sec-head { display: grid; gap: 10px; margin-bottom: 32px; max-width: 760px; }
.sec-head h2 { font-size: clamp(28px, 3.6vw, 44px); text-transform: uppercase; }
.sec-head p { color: var(--muted); }

.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); counter-reset: s; border-top: 2px solid var(--ink); }
.steps li { counter-increment: s; padding: 18px 20px 0 0; display: grid; gap: 8px; align-content: start; }
.steps li + li { padding-left: 20px; border-left: 1px solid var(--line); }
.steps li::before { content: "0" counter(s); font: 600 14px var(--font-mono); color: var(--accent); background: var(--panel); justify-self: start; padding: 3px 7px; border-radius: 3px; }
.steps h3 { font-size: 21px; text-transform: uppercase; }
.steps p { color: var(--muted); font-size: 15px; }
@media (max-width: 900px) {
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .steps li:nth-child(3) { border-left: 0; padding-left: 0; }
  .steps li:nth-child(n+3) { padding-top: 24px; }
}
@media (max-width: 520px) {
  .steps { grid-template-columns: 1fr; }
  .steps li + li { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); padding-top: 18px; margin-top: 18px; }
}

.plants { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.plant { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 26px; display: grid; gap: 12px; align-content: start; }
.plant h3 { font-size: 30px; text-transform: uppercase; display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.plant h3 span { font: 500 12px var(--font-mono); color: var(--muted); letter-spacing: 0.1em; }
.plant ul { margin: 0; padding-left: 18px; color: var(--muted); display: grid; gap: 4px; }
@media (max-width: 720px) { .plants { grid-template-columns: 1fr; } }

.spec { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; border: 1px solid var(--line); border-radius: var(--r); background: var(--surface); overflow: hidden; }
.spec > div { padding: 22px; display: grid; gap: 6px; align-content: start; }
.spec > div + div { border-left: 1px solid var(--line); }
.spec b { font: 600 20px var(--font-display); text-transform: uppercase; }
.spec p { color: var(--muted); font-size: 15px; }
@media (max-width: 820px) {
  .spec { grid-template-columns: 1fr; }
  .spec > div + div { border-left: 0; border-top: 1px solid var(--line); }
}

.final { background: var(--panel); color: var(--on-panel); }
.final .wrap { display: flex; justify-content: space-between; align-items: center; gap: 24px; flex-wrap: wrap; padding-block: 48px; }
.final h2 { font-size: clamp(26px, 3.4vw, 40px); text-transform: uppercase; max-width: 18em; }
.final p { color: color-mix(in srgb, var(--on-panel) 70%, transparent); margin-top: 8px; }

.foot { padding-block: 28px; font-size: 13px; color: var(--muted); }
.foot .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.stamp .stamp-eyebrow { color: inherit; opacity: 0.6; }
.sec.sec-tight { padding-top: 0; }